Data Storage Devices (DSDs) are often used to record data on or to reproduce data from a recording media. As one type of DSD, a disk drive can include a rotating magnetic disk and a head actuated over the disk to magnetically write data to and read data from the disk. Such disks include a plurality of radially spaced, concentric tracks for recording data.
Shingled Magnetic Recording (SMR) has been introduced as a way of increasing the amount of data that can be stored in a given area on a disk by increasing the number of Tracks Per Inch (TPI). SMR increases TPI by using a relatively wide shingle write head to overlap tracks like roof shingles. The non-overlapping portion then serves as a narrow track that can be read by a narrower read head.
Although a higher number of TPI is ordinarily possible with SMR, the higher track density can create additional problems. For example, the closer spacing of tracks in an SMR region can worsen Adjacent Track Interference (ATI) where the writing of data on an adjacent track negatively affects the data written on a target track. One way of approaching this problem includes Inter-Track Interference Cancellation (ITIC) where data is read in the adjacent track to account for its effect in the target track. However, since ITIC typically involves additional reading and accounting for data in the adjacent track, more processing resources are usually consumed in addition to either the additional time to read the adjacent track or the additional cost of providing an extra read head to read the data in the adjacent track.
Another problem encountered with SMR involves Wide Area Track Erasure (WATER). WATER results in data being erased from adjacent tracks near a track being written due to interference from the magnetic field of the write head. The problems caused by WATER are exacerbated when tracks are repeatedly rewritten. DSDs using SMR are ordinarily more susceptible to WATER than conventional disk drives due to the combination of narrower tracks and a wider shingle write head having a stronger magnetic field.